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//
// Novell.Directory.Ldap.LdapModification.cs
//
// Author:
//   Sunil Kumar (Sunilk@novell.com)
//
// (C) 2003 Novell, Inc (http://www.novell.com)
//

namespace Novell.Directory.Ldap
{
    /// <summary>
    ///     A single add, delete, or replace operation to an LdapAttribute.
    ///     An LdapModification contains information on the type of modification
    ///     being performed, the name of the attribute to be replaced, and the new
    ///     value.  Multiple modifications are expressed as an array of modifications,
    ///     i.e., <code>LdapModification[]</code>.
    ///     An LdapModification or an LdapModification array enable you to modify
    ///     an attribute of an Ldap entry. The entire array of modifications must
    ///     be performed by the server as a single atomic operation in the order they
    ///     are listed. No changes are made to the directory unless all the operations
    ///     succeed. If all succeed, a success result is returned to the application.
    ///     It should be noted that if the connection fails during a modification,
    ///     it is indeterminate whether the modification occurred or not.
    ///     There are three types of modification operations: Add, Delete,
    ///     and Replace.
    ///     <b>Add: </b>Creates the attribute if it doesn't exist, and adds
    ///     the specified values. This operation must contain at least one value, and
    ///     all values of the attribute must be unique.
    ///     <b>Delete: </b>Deletes specified values from the attribute. If no
    ///     values are specified, or if all existing values of the attribute are
    ///     specified, the attribute is removed. Mandatory attributes cannot be
    ///     removed.
    ///     <b>Replace: </b>Creates the attribute if necessary, and replaces
    ///     all existing values of the attribute with the specified values.
    ///     If you wish to keep any existing values of a multi-valued attribute,
    ///     you must include these values in the replace operation.
    ///     A replace operation with no value will remove the entire attribute if it
    ///     exists, and is ignored if the attribute does not exist.
    ///     Additional information on Ldap modifications is available in section 4.6
    ///     of <a href="http://www.ietf.org/rfc/rfc2251.txt">rfc2251.txt</a>
    /// </summary>
    /// <seealso cref="LdapConnection.Modify">
    /// </seealso>
    /// <seealso cref="LdapAttribute">
    /// </seealso>
    public class LdapModification
    {
        /// <summary>
        ///     Returns the attribute to modify, with any existing values.
        /// </summary>
        /// <returns>
        ///     The attribute to modify.
        /// </returns>
        public virtual LdapAttribute Attribute
        {
            get { return attr; }
        }

        /// <summary>
        ///     Returns the type of modification specified by this object.
        ///     The type is one of the following:
        ///     <ul>
        ///         <li>LdapModification.ADD</li>
        ///         <li>LdapModification.DELETE</li>
        ///         <li>LdapModification.REPLACE</li>
        ///     </ul>
        /// </summary>
        /// <returns>
        ///     The type of modification specified by this object.
        /// </returns>
        public virtual int Op
        {
            get { return op; }
        }

        private readonly int op;
        private readonly LdapAttribute attr;

        /// <summary>
        ///     Adds the listed values to the given attribute, creating
        ///     the attribute if it does not already exist.
        ///     ADD = 0
        /// </summary>
        public const int ADD = 0;

        /// <summary>
        ///     Deletes the listed values from the given attribute,
        ///     removing the entire attribute (1) if no values are listed or
        ///     (2) if all current values of the attribute are listed for
        ///     deletion.
        ///     DELETE = 1
        /// </summary>
        public const int DELETE = 1;

        /// <summary>
        ///     Replaces all existing values of the given attribute
        ///     with the new values listed, creating the attribute if it
        ///     does not already exist.
        ///     A replace with no value deletes the entire attribute if it
        ///     exists, and is ignored if the attribute does not exist.
        ///     REPLACE = 2
        /// </summary>
        public const int REPLACE = 2;

        /// <summary>
        ///     Specifies a modification to be made to an attribute.
        /// </summary>
        /// <param name="op">
        ///     The type of modification to make, which can be
        ///     one of the following:
        ///     <ul>
        ///         <li>
        ///             LdapModification.ADD - The value should be added to
        ///             the attribute
        ///         </li>
        ///         <li>
        ///             LdapModification.DELETE - The value should be removed
        ///             from the attribute
        ///         </li>
        ///         <li>
        ///             LdapModification.REPLACE - The value should replace all
        ///             existing values of the
        ///             attribute
        ///         </li>
        ///     </ul>
        /// </param>
        /// <param name="attr">
        ///     The attribute to modify.
        /// </param>
        public LdapModification(int op, LdapAttribute attr)
        {
            this.op = op;
            this.attr = attr;
        }
    }
}